Climate and Architecture Geog410 Dr Ye

Primitive Constructions Hot-wet Climate: small annual variation of temperature, intense solar radiation, high humidity, and heavy rainfall House: maximum ventilation and shade, movable shade or open walls (catch breeze), water- proof roof, stilted (prevent flooding from nearby river), materials have little or no heat storage capacity

Primitive Constructions Tropical Desert: intense solar radiation, high temperature during day, cold at night House: thick walls, minimum window space, house close together for maximum shade, mud and straw are basic materials. Example: narrow street in Arab communities Valleys are parallel to prevailing winds (minimize wind exposure), shaded side walk, short walking distance, courtyard with greenery, compact geometry, use high albedo materials as building surfaces. Dense and substantial thickness walls release heat during night, block sun during day, indoor temp lag behind outdoor.

Savanna areas: summer wet, winter dry, seasonal rain of varying intensity Houses: dome or cone shaped to facilitate drainage during wet spells; materials are grass, mulch, and branches and animal skins (now use cement block)

Mediterranean Climate Zone: combination of requirements for arid regions with those of places that experience a cool, wet season. House is represented by Roman times’ older dwellings: has a central open courtyard-shaded during day, retain heat at night. Fountain and/or pool in the courtyard (microclimate)

Outside of tropical areas, primitive shelters were necessary to overcome the problem of cold. Polar Region: Inuit Igloo: hemispheric shape minimizes heat loss by providing maximum volume with a minimum of surface area and effectively resists the strong Arctic wind

Snow offers excellent insulating properties. Often several igloos are grouped closely together and interior, protected passages connect one structure to another with only one main entrance for that particular grouping of igloos. The main entrance is protected by a snow wall that is perpendicular to the wind direction and is usually oriented on the windward side of the structure, parallel to the wind direction to avoid snow drifts found on the leeward of the structure. The entrance on purposely lower than the surface of the snowpack and provides access to a series of transitional spaces, called iglik. As one enters the igloo, through the buried and curved tunnel, the floor rises until the iglik is reached through a low bulkhead. The gradual rising floor elevation allows a pragmatic stratification of the air mass within the igloo that collects the warmer indoor air within the iglik and confines the cooler air to the natiq. The hanging skins and the final low bulkhead, separating the main space, help further to confine and tratify the air mass and block draughts from the exterior. Outside Air is -50C, the top of dome can be as high as 15C, and close to zero in natiq. It is constructed of dry snow blocks that piled one on the other in an inward spiral, snow has a low conductivity and help conserve interior temp. (59F or 15C). in summer, they use turf, earth and driftwood to construct sod-roofed dugouts.

A small window of ice that is curved from an available ice pack and sealed within the hemispheric envelope facing the sun. During summer, skins are hung on the interior of the dome to create a relieving dark environment (long daylight). Comparison of temp insides and outside of an igloo Diurnal temperature range is smaller and maximum and minum lags behind the outside air temperature

Modern Constructions Climate and modern structures Construction of a home or business that uses its background climatic environment as a resource benefits in many ways: economic (decreased energy costs), aesthetic (exhibited by landscape design). Basic element: solar radiation. Cold region welcomes direct solar radiation inside house and on the walls; hot climate avoid it.

How to calculate solar angle at give day of the year at a location?

Solar altitude = 90 – (latitude +/- declination of sun (negative sign is used when both in the same hemisphere; positive sign used if they are on diff. hemisphere). Ex, in winter solstice, when sun is overhead 23.5S, the altitude of the noon sun at 41N is altitude=90- (latitude+23.5)=90 -( )=25.5 In summer solstice, overhead at 23.5N; altitude=90-( )=72.5

Correct use of overhangs (climatology)

Reduce ventilation and increase insolation during winter; let in cooling breeze and shield the insolation during summer.

Example of house design in hot and arid climate North/south oriented building-maximizing majority of wall surface of the structure facing either east or west, the exposure to south or north is minimal, little wall to charge glaring sun from south. Spacing between adjacent dwellings east-west of one another should created mutual shading of the east-west wall to reduce intense morning and afternoon solar radiation. Space should be 3 times the height of the buildings allowing sun to strike east- and west-facing walls between 11:00and 13:00 hours Solar protect of the walls at either end of the row of the adjacent dwelling can be “shadowbelt” (for example, trees, for shading and noise and pollution barrier).

Heating and cooling degree days: indicators of the amount of energy consumed for space heating and cooling Heating Degree Days (HDD): accumulation of daily amount of degrees below 65°F each year HDD=65°-Tm if Tm is below 65° HDD=0° if Tm is above 65° Cooling Degree Days (CDD): accumulation of daily amount of degrees above 65°F each year CDD = Tm-65°F if Tm> 65°F CDD = 0° if Tm <65°F

Indoor temperature has smaller diurnal variations The maximum and minimum temperature occur later indoor Which material has a better insulation effect and why?

Climate Zones

house design specific for different climate zones

Urban Climate Concrete, asphalt, and glass replace natural vegetation Structures of vertical extent replace a largely horizontal interface Large amounts of energy are imported and combusted Combustion of fossil fuels creates pollution

Modified energy flow in urban environment Lowe albedo (reflectivity of a surface to solar radiation Greater conduction and storage

Decrease LE Higher Bowen Ratio (H/LE) Indoor heating added warmth to city More pollution,-more condensation nucleus- cloudier -Reduced loss of longwave radiation to space-warmer at night Urban heat island: the air temperature in urban areas is higher than the surrounding rural areas.

Lapse Rate: the rate of air temperature decreases with height Inversion: the air temperature increases with height